Details of how the 40% increase in Britain's aid spending on Afghanistan have been unveiled by the government, as the motivation for the shift begins to be questioned by critics.
International development secretary Andrew Mitchell is spending the day touring some of the projects in and around Kabul which the extra money will be spent on.
Unveiling the details of the proposed boost from the current £500 million budget, he said the extra money would be used to stabilise insecure areas, stimulate the Afghan economy and improve the effectiveness of the Afghan government.
"Using the UK's aid budget to secure progress in Afghanistan will be my number one priority," Mr Mitchell said.
"Well-spent aid is in our national interest. Nowhere in the world is this case clearer than in Afghanistan.
"Whilst the military is there to bring much-needed security, peace will only be achieved through political progress backed by development."
The emergency Budget confirmed international aid and spending on the NHS are the only two areas protected from sweeping spending cuts across Whitehall.
Some are beginning to suggest the ring-fenced aid budget is being undermined by the concentration on Afghanistan.
Writing in an article for politics.co.uk, development expert Hannah Redmond warned that the 40% increase in aid "seems questionable".
"Afghanistan would and should receive aid as a country with great poverty, but the level DfID plan to increase seems disingenuous and linked to military advancement and political goals rather than any humanitarian concern for the Afghan people," she suggested.
Mr Mitchell is visiting Afghanistan alongside foreign secretary William Hague to attend the Kabul conference on progress and development in Afghanistan.